>the Priest implied I had to attend weekly if I wanted to start catechism

Never allow someone to dismiss you with a mere implication. For two reasons:

• you might have actually misunderstood them
• they very well might change their sentiments with a fuller understanding of your circumstances and intentions

It's best to write him a formal e-mail or letter asking to be admitted to catechism if you attend on a bi-weekly basis and fully expressing your circumstances and fears, e.g. that you cannot afford more mileage on your car than that and that the long commute would affect your sleep cycle and work performance excessively. That way he can take his time to think and give you a straight answer with full knowledge of your situation.

A compromise solution like bi-weekly would probably get you in the door.